Hi ML

If you are close; I have a hybrid that I plan on selling soon. It is a Raliegh Venture; with a few upgrades.

With regards to the older mountain bike: look for one with no suspension. The Bell brand Kevlar belted cruiser tires from Wal-mart are inexpensive, last a long time and are very resistant to punctures. They usually have them in stock in 26" (ISO 559) and 700c (ISO 622) sizes.

Regard women vs men for bike sizing. Generally women have longer legs and shorter torsos for a given overall hieght. Thus, women will generally be more comfortable on a smaller (short length) bike, with the seat set higher. Bikes are very adjustable, seat hieght is very inexpensive to change, reach (seat to handle bars) is not difficult to change, but a bit more expensive.

Inseam - crotch to floor with the shoes you'll be using to ride. A tape measure and ruler or book work well. Pull (but not hard) the ruler or book up to the crotch, and measure to the floor. I like to have my saddle set so that with the pedals at the bottom of thier stroke, the saddle is about 1" less than this inseam measurement. Admittedly, I prefer the saddle high due to knee problems; but that is also the most efficient. Of course, I can not touch the ground when seated.